Bowl centrifuge



Sept. 27, 1966 G. HlLLER 3,275,230

BOWL CENTRIFUGE Filed July 27, 1964 5 Sheets-Sheet 1 FIG. 3

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HTroRnEy Sept. 27, 1966 e. HILLER 3,275,230

BOWL CENTRIFUGE Filed July 27, 1964 3 Sheets-Sheet 2 LI K4 FIG. 5 l

5 Sheets-Sheet 5 Filed July 27, 1964 N QN Q E liililunfilliii IDVEH OR crcma H\\ev HTToRnEys United States Patent Q 3,275,230 BOWL CENTRIFUGE Georg Hiller, Vilsbiburg, Lower Bavaria, Germany, assignor to Flottweg-Motoreuwerk Dr. Georg Bruckmayer, Vilsbiburg, Lower Bavaria, Germany Filed July 27, 1964, Ser. No. 385,333 Claims. (Cl. 233-7) The present invention relates to a bowl centrifuge which is provided with a plurality of disks within a fully closed bowl or packet which has a conical shape at least at one end thereof, and with a conveying spiral which extends outside of the operating range of the disks and is rigidly but removably secured to the disks. These parts may be rotated together at a speed different from that of the jacket of the centrifuge and thus relative to this jacket. In place of a single spiral, the centrifuge may also be provided with several spirals and, if desired, also with a conveying spiral which serves for a preclarification of liquids.

By providing the inside of a centrifuge with such disks, it is possible to improve and especially to accelerate the separation of solid materials from liquids. This advantage is, however, counteracted by the fact that in actual practice it is very difiicult to remove the solids which are deposited within the area of the maximum diameter of the disk-shaped inserts and to convey them from this area in the direction toward the outlet of the centrifuge. This is due to the fact that the disk set of a known centrifuge of the above-mentioned type is surrounded by an element for supporting the spiral and that this supporting element must be provided with bores or other apertures to permit the solid materials which have been deposited at the inside of the spiral to be passed into the conveying chamber. Even if the supporting element of the spiral is extensively perforated and consists, for example, of latticework, it cannot be avoided that relatively large surfaces remain on which some of the solids will be deposited. If these known centrifuges are employed for separating perishable materials, for example, in the production of foodstuff or in the chemical or pharmaceutic industry, it is absolutely necessary from time to time, and at least whenever they are stopped, to open the centrifuges and to clean them out completely. Since these centrifuges are of a rather complicated construction, such cleaning operations are very difficult and therefore also consume a considerable length of time. In addition, the spiral parts are subject to considerable wear and must therefore from time to time be replaced by others or be reconditioned by welding additional material thereon so as to regain their original diameter. Especially this welding operation renders such centrifuges very expensive since it results in distortions of the supporting element of the spiral so that at least this element has to be straightened.

It is an object of the present invention to provide a full-jacket centrifuge which overcomes the above-mentioned disadvantages, requires considerably less service than any of the known centrifuges of the same general type of construction, and is especially designed so that the structure of the entire centrifuge is as simple as possible.

For attaining this object, the invention provides that the disks themselves form the supporting elements of the spiral or spirals. Since it is now no longer necessary to connect the supporting element of the spiral or spirals to the disks in a manner so .as to be removable therefrom, but each spiral is now removably connected directly to the disks, all of the mentioned disadvantages of the previous centrifuges of this type are eliminated in an extremely simple manner.

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One advantageous feature of the invention consists in forming the spiral of a plurality of parts which are spaced from each other.

The various features of the invention will become more clearly apparent from the following detailed description thereof which is to be read with reference to the accompanying drawings, in which:

FIGURE 1 shows a partial section of a centrifuge according to the invention which is provided with disks which are spaced from each other by spacing plates which project beyond the periphery of the disks and the projecting parts of which are twisted so as to form parts of a spiral;

FIGURE 2 shows a cross section of FIGURE 1;

FIGURE 3 shows a view similar to FIGURE 1 of a modification of the invention, in which a continuous spiral strip which is composed of four quadrants is secured to outer extensions of spacing plates and winds spirally around the outer edges of the set of disks;

FIGURE 4 shows a cross section of FIGURE 3;

FIGURE 5 shows another view similar to FIGURE 1 of another modification of the invention, in which a continuous spiral strip is inserted into grooves which are provided in the outer edge portions of the disks;

FIGURE 6 shows a cross section of FIGURE 5; while FIGURE 7 shows a longitudinal section of a doublecone full-jacket centrifuge according to the invention, in which the spiral parts which are connected to the disks are designed in accordance with FIGURES 1 and 2.

As illustrated in FIGURES 1 and 2 of the drawings, the jacket 1 of the centrifuge which is adapted to be rotated at a certain speed contains a central support 2 for a plurality of disks 3 which is likewise rotatably mounted and adapted to be driven at a speed different from that of jacket 1 so that the disks 3 revolve relative to the jacket 1. The adjacent disks 3 are spaced from each other by spacing plates, the ends 4 of which project beyond the periphery of the set of disks 3 and are twisted so as to form parts of an interrupted spiral.

FIGURES 3 and 4 show a modification of the invention in which the spiral is composed of four quadrant strips 5 which are secured to the outer extensions of spacing plates 6.

A further modification of the invention as shown in FIGURES 5 and 6 comprises a continuous spiral strip 7 which is inserted into grooves 8 which are cut into the outer edges of the disks 3.

A full-jacket centrifuge which is provided with disks according to the invention is illustrated in FIGURE 7 and comprises an outer bowl or jacket 10 which is rotatably mounted and contains coaxially thereto a hollow shaft 11 which is likewise rotatably mounted and carries two spiral conveyers 12 and 13 and disk-shaped inserts 20 of a construction in accordance with the disks 3 as shown in FIGURES 1 and 2. The slurry of liquid and solids is fed into the centrifuge through a central feed pipe 14 and passes into a distributing chamber 15 from which it enters through openings 16 in the wall of the hollow shaft 11 into the settling chamber. Due to the difference in speed at which the jacket 10 and the hollow shaft 11 are driven, the coarse solids which are deposited on the inner surface of the jacket 10 are then conveyed by the conveyer spiral 12 in the settling chamber in the direction toward the outlet openings 17 through which they are discharged, while the finer solids pass together with the liquid from the settling chamber through one or more overflows 28 into a cylindrical chamber 19 which is outwardly limited by the jacket 1 which is rigidly secured to or integral with the conical jacket 10. This chamber 19 contains the disk-shaped inserts 20 which correspond to the disks 3 according to FIGURES 1 and 2. At the outer periphery of these disks conveyer elements 21 are mounted which correspond to the twisted spiral parts 4 according to FIGURES 1 and 2. When the jacket 1, 10 and the hollow shaft 11 revolve at different speeds relative to each other, the fine solids which are deposited on the outer jacket 1 in the chamber 19 are conveyed in the direction toward the conveyer spiral 13 and are then discharged through the outlet openings 22. The clarified liquid is discharged from the apparatus through one or more channels 23.

The speed at which the solids may be removed from the liquid may be' varied by varying the pitch of the spiral surfaces or by varying the speed of the driven parts. Since the individual parts are rigidly although removably connected to each other, they form a compact unit which may be easily balanced in sta tic and dynamic respects.

Although the invention has only been described with reference to certain preferred embodiments thereof, it is evident that it is the basic concept of the invention to provide the disks, which as such only affect the precipitation of the soilds, directly with spirally shaped conveyer elements which are effective in the chamber between the outer edges of the disks 3 or 20 and the inner wall surface of the jacket 1 and convey the separated solids in the axial direction. According to the invention the disks are therefore also employed as supports of the spiral conveyer elements.

Although my invention has been illustrated and described with reference to the preferred embodiments thereof, I wish to have it understood that it is in no way limited to the details of such embodiments, but is capable of numerous modifications within the scope of the appended claims.

Having thus fully disclosed my invention, what I claim 1s:

1. A bowl centrifuge having a full outer jacket with at least a part thereof being of a conical shape, means for rotatably mounting said jacket, a central supporting member mounted within and rotatable relative to said jacket, a set of disks secured to said supporting member, spiral means removably secured directly to said set of disks and projecting from the outer periphery thereof, and means for rotating said jacket and said supporting member with said disks and said spiral means thereon at different speeds.

2. A bowl centrifuge as defined in claim 1, in which said spiral means consist of a plurality of sections of a spiral spaced from each other.

3. A bowl centrifuge as defined in claim 2, further comprising spacing plates separating said disks from each other and having parts projecting beyond the outer periphery of said disks, said projecting parts being bent so as to form said spiral sections.

4. A bowl centrifuge as defined in claim 1, in which said spiral means consist of at least one spiral strip winding around the outer periphery of said set of disks and connected to said disks.

5. A bowl centrifuge as defined in claim 1 in which said spiral means consist of at least one continuous spiral strip winding around the outer periphery of said set of disks and composed of a plurality of spiral sections secured to each other and to said disks.

References Cited by the Examiner UNITED STATES PATENTS 837,695 12/1906 Ljungstrom 233-7 1,780,655 11/1930 Nyrop 233-7 2,711,854 6/1955 Kjellgren 2337 M. CARY NELSON, Primary Examiner.

H. KLINKSIEK, Examiner. 

1. A BOWL CENTRIFUGE HAVING A FULL OUTER JACKET WITH AT LEAST A PART THEREOF BEING OF A CONICAL SHAPE, MEANS FOR ROTATABLY MOUNTING SAID JACKET, A CENTRAL SUPORTING MEMBER MOUNTED WITHIN SAID ROTATABLE RELATIVE TO SAID JACKET, A SET OF DISKS SECURED TO SAID SUPPORTING MEMBER, SPIRAL MEANS REMOVABLY SECURED DIRECTLY TO SAID SET OF DISKS AND PROJECTING FROM THE OUTER PERIPHERY THEREOF, AND MEANS FOR ROTATING SAID JACKET AND SAID SUPPORTING MEMBER WITH SAID DISKS AND SAID SPIRAL THEREON AT DIFFERENT SPEEDS. 